Electric switch



H. B. STILLMAN. ELECTRIC SWITCH. APPLICATION FILED MAY26, I919.

INVENTOR /9 2/ V 3: ZZQ/Q/QYEQYMZ 6W .25 A5" A l (r 9 3 I EY UNITED STATES PATENT OFFICE.

HARRY BARNUM STILLMAN, 0F PLAINVIL-LE, CONNECTICUT, ASSIGNOR TO THE TRUM- IBULL ELECTRIC MANUFACTURING COMPANY, OF PL-AINVILLE, CONNECTICUT, A

CORPORATION OF CONNECTICUT.

ELECTRIC SWITCH.

Specification of Letters Patent.

Patented Oct. .5, 1920.

Application filed May 26, 1919. Serial No. 299,845.

To all whom it may concern:

Be it known that I, HARRY BARNUM STILLMAN, a citizen of the United States of America, residing at Plainville, Conn, have invented a new and useful Electric Switch, of which the following is a specification.

My invention relates particularly to switches of the inclosed type.

The objects of the invention are to provide a simple inexpensive form of quick break switch mechanism and one in which it will be impossible to open the box without first throwing the switch to the off position.

In the preferred form of the invention the movable switch element is supported by a spring arm overstanding the switch base and supported at its end by the adjacent wall of the box and the operation of this movable element is efiected by a swinging lever which has a lost motion connection with a switch throwing handle.

Various other features of the invention will appear as the specification proceeds.

In the accompanying drawing I have illustrated the invention embodied in one of its practical preferred forms but would have it understood that various modifications may be made without departure from the true spirit and scope of the invention.

In this drawing: Figure 1, is a plan view of the complete switch, with the cover of the switch box broken away to disclose the interior mechanism.

Fig. 2, is a broken sectional view taken substantially on the plane of the line 22 of Fig. 1 and showing the switch in the opencircuit position.

Fig. 3, is a similar view showing the switch in the closed-circuit position.

Fig. 4., is a broken and part sectional view illustrating how'the switch is automatically thrown to open position when the cover is opened.

Fig. 5, is a broken cross sectional view taken substantially on the plane of the line 5-5 of Fig. 1.

5 designates the switch base made of suitable insulating material and supporting on its face two pairs of spaced contacts 6 and 7 gagement with the relatively stationary contacts.

The movable switch element is supported by a spring arm 11, constructed in this instance, of a relatively wide strip of spring metal having an angularly bent portion 12. at one end secured at 13 to the lower wall of the box 14 which incloses the switch mechanism and curved or curled under at its opposite end to provide a curved or inclined cam shoulder 15. The movable switch element is shown secured to this supporting spring by a screw 16 passed from the under side of the cross bar through the curved end of the spring and into engagement with a nut 17 located inside the bend or curve in the end of the spring. .This supporting spring exerts its tension to lift the movable switch element away from the relatively stationary contacts and the outward movement of the movable switch element is limited, in this particular disclosure, by stops 18 provided on the outer ends of the guide pins 9.

l9 designates the switch operating lever which is pivoted at 20 at a point over the free end of the supporting spring and carlever 19 and provided at its outer end with a suitable handle 23 and at its inner end with spaced stop shoulders 2l-25 for engagement with a pin 26 on the switch operating lever, said pin being shown as a continuation of the axis on which the roller 21 is journaled. This construction it will be evident provides a lost motion connection between the handle lever and the switch operating lever.

The handle lever and switch operating lever are shown both supported on a bracket 27 overstanding the switch base and secured at its opposite ends at 28 to the opposite side walls of the switch box. The pivotal supports for the two levers are shown as screws or rivets 29 (Fig. 1) secured to integral dependent lugs 30 struck down from the top of the supporting bracket 27.

The switch box 14 is provided, in the present disclosure, with a hinged cover 31 hav ing a slot 32 therein for the passage of the 7 of into engagement with the in 26 on the swinging operating lever which thereupon moves with the handle, causing the roller 21 to ride over the cam face 15 on-the end of the ,sfirmg and to depress the switch spring. y this cam movement the bridging contacts on the movable switch element are forced into engagement with the stationary switch contacts, as indicated in Fig. 3, and as the roller passes up the cam face and onto the straight portion of the spring adjacent thereto, the switch will be held in the closedcircuitposition (Fig. 3). In this condition of the parts the cam shoulder 33 on the outer end of the handle overstands the solid portion of'the' cover and holds the cover in its closed position. The switch is opened by ipulling down on the handle in Fig. 3, the

rstpart of the handle movement serving to take up the lost motion between the shoulder 25 and pin 26. As said lost motion is taken up, the switch operating lever 19 moves with the handle until the lever 19 reaches the center of its swinging movement and the roller passes on to the inclined or cam portion of the supporting s ring whereupon the spring asserts itsel an snaps the lever 19 u ward and free ofthe cam portion, as indicated in Fig. 2, this free movement of the operating lever'being permitted by reason of the-lost motion be tween the pin 26 and the shoulder 24. In this way a'quick snap of the switch is pro- .duced in the circuit-opening movement.

In case it is attem ted to open the switch box without first tl frowing the switch to open-circuit position, the cover acting against the cam 33, as indicated in Fig. 4, throws the switch handle downwardly,. thereby automatically throwing the switch to the open-circuit position.

I claim:

1. In a switch of the character described, the combination of a 'switchbox, switch. mechanism mounted in said box and comprising relatively stationary contacts a relatively movable switch element for cotiperation with the stationary contacts, a spring secured to the side wall of the'box and supportin said movable switch element and insulate therefrom and means engaging with said supporting spring for forcing the movable switch element into engagement with the relatively stationary contacts.

2. In-a switch of the character described,

the combination of a switch box, a switch base mounted in saidbox, contacts on said base, a movable switch element for cooperation with the contacts, a support for said movable switch element insulated therefrom and comprising a relatively flat strip of spring metal projecting over and spaced above the switch base and means for depressing said spring support to force the movable element into engagement with the contacts.

3. In combination with a switch base andcontacts mounted thereon, a movable switch element for enga ement with said contacts, a support forsaicf movable element comprising a spring arm connected with the movable element and provided with a curved portion adjacent the point of connection 'with the movable element and operating spring arm, a roller carried by said lever for engagement with the spring arm and a swinging operating handle pivoted substantially concentric to the lever and having a lost motion connection with said lever.

5. In combination, a switch box, switch mechanism mounted in said box and comprising relatively stationary and movable contacts, a spring arm secured to one wall of the box and connected with the movable switch element and insulated therefrom and a lever pivotally mounted on the box for depressing the-spring arm to carry the movable switch element into engagement with the stationary contacts.

6. In combination, a switch casin a movable element of an electric switc a spring arm connected to said movable eleinent and to the casing, a swinging lever adapted when thrown in one direction to force the movable switch element into the circuit-closed position and adapted when thrown in the opposite direction to stand free of the movable switch element, a swim ing operating lever pivoted substanti y concentric to said first lever, one of said levers carryi a pin and the other lever having space shoulders for engagement with said pin to thereby provide a lost motion connection between the levers.

7. In an electric switch, the combination of a spring supported movable switch element provided with a cam shoulder, a pivoted lever, over-standing said movable switch element and having a bearing upon cam shoulder when operated in the reverse direction and an operating handle having a lost motion connection with said swinging lever-and comprising spaced shoulders and a pin adapted to be engaged thereby.

8. In an electric, switch, a switch box, switch mechanism mounted in said box and including a movable switch element, a bracket secured to the switch box and overstanding the switch mechanism therein, lugs dependent from said bracket, swinging levers pivoted on said dependent lugs, one of said levers being provided with an operating handle and having a lost motion connection with the other lever and said other lever having a connection with the movable switch element for operating the same.

9. In combination with the movable element of an electric switch, a swinging lever adapted when thrown in one direction to force the movable switch element into the circuit-closed position and adapted when thrown in the opposite direction to stand free of the movable switch element, a swinging operating lever pivoted substantially concentric to said first lever, one of said levers carrying a pin with a roller mounted thereon and the other lever having spaced shoulders for engagement with said pin to thereby provide a 10st motion connection between the levers.

10. In an electric switch, the combination of a box, a spring arm supported by a wall of 'said box and provided with a bearing face, a movable switch element carried by the movable end of said arm and having oppositely disposed contact tips, a swinging lever over-standing said spring arm and having a bearing coacting with the bearing face of said spring arm when swung in one direction and adapted to swing free of said bearing face when operated in the reverse direction and an operating handle having a lost motion connection with said swinging lever.

- HARRY BARNUM STILLMAN. 

